Research on Electrochemical Corrosion and Passive Behavior of CoCrFeNi High-Entropy Alloy Compared with 304 Stainless Steel in a NaCl Environment

The difference in the electrochemical corrosion and passive behavior of CoCrFeNi high-entropy alloy and 304 stainless steel in a chloride environment was systematically investigated by using electrochemical measurements, immersion test and surface analysis technology. The results demonstrate that in comparison with 304 SS, the passive film formed on CoCrFeNi HEA exhibits more protective capability. The CoCrFeNi HEA with a compact and thick passive film exhibits lower passive current density, higher film resistance and polarization resistance, implying a lower corrosion rate and outstanding corrosion resistance compared to the 304 SS. The difference in the corrosion behavior of the two alloys is related to chemical composition, grain size, and passive film.